Guide workflow for drivers
Use the guide, not a guess.
A starting point for first-time visitors: use the free browser lookup, then follow the published references and scan-result guidance without treating a code as a parts verdict.
Quick definitions
Diagnostic terminology
These plain-English definitions explain labels used in CrankKey’s scan reports.
CrankKey provides general diagnostic information; it does not confirm a diagnosis for a specific vehicle.
- Pending DTC
- A code stored when the OBD system detects a potential malfunction. The system may use later drive cycles to evaluate it before confirming a malfunction.EPA OBD DTC definitions (40 CFR § 86.010-2)
- Permanent DTC
- A DTC that corresponds to a MIL-on DTC and is stored in non-volatile memory. Only the vehicle’s OBD system can erase it; a scan tool or other human interaction cannot.EPA OBD DTC definitions (40 CFR § 86.010-2)
CrankKey’s connected scan is read-only and does not clear codes. A permanent DTC is erased only by the vehicle’s OBD system after its requirements are met; clearing codes is not a repair, and faults may return.
- Freeze Frame Data
- A recorded snapshot of vehicle operating conditions associated with a fault or DTC. It may be unavailable on some vehicles or in some scans. The cited federal OBD rule applies to heavy-duty engines used in applications over 14,000 lb GVWR.EPA heavy-duty OBD requirements for engines used in applications over 14,000 lb GVWR (40 CFR § 86.010-18)
- Module
- A vehicle computer, also called an electronic control unit (ECU) or electronic control module, that controls one or more electrical systems. A scan response confirms that a computer answered, but not which module answered.EPA-approved California Title 13, Division 3, Chapters 3.5–3.7 compilation (ECU definition)
- Diagnostic Trouble Code (DTC)
- An OBD-II diagnostic trouble code (DTC) identifies a detected condition in a monitored component or system. It is a starting point for testing, not a failed-part finding or diagnosis.
- Malfunction Indicator Lamp (MIL)
- The malfunction indicator lamp (MIL), commonly called the check-engine light, is a warning governed by the vehicle’s fault logic. A steady or flashing light changes the urgency, but the light alone is not a diagnosis.
- Readiness
- Readiness is the status of an automated self-check for an emissions-related subsystem. “Ready” means the monitor completed its routine; “not ready” means it has not completed, not that a part failed or an inspection result is guaranteed.
- OBD-II Code Status
- A code status tells you where the vehicle’s monitoring logic is in its process: pending means detected but not confirmed, confirmed means the fault was verified and stored, and permanent means it is retained until the vehicle’s OBD system verifies that the fault is no longer present.
- Fuel trim
- A value describing an engine controller’s adjustment to fuel delivery. Its meaning depends on the vehicle and the scan context.
- Coolant temperature
- A reported temperature value for the engine coolant. Check the vehicle service manual for model-specific interpretation.
- SAE J2012
- SAE J2012 describes standardized diagnostic trouble-code definitions. Its scope does not validate CrankKey’s decoder or vehicle coverage.Official SAE J2012_202509 page
- ISO 15031-6:2015
- ISO 15031-6:2015 describes standardized DTC formats and definitions for emissions-related diagnostics. Its scope does not validate CrankKey’s decoder or vehicle coverage.Official ISO 15031-6:2015 page
- CARB OBD II regulations
- The CARB OBD II regulations index points to applicable current California regulations; applicability depends on the vehicle and jurisdiction. CrankKey does not claim EPA or CARB compliance.Official CARB OBD II regulations index